Device for exposing small rollable bodies to sputtering

ABSTRACT

Cylindrical ceramic blanks are fed endwise down grooves in a vibratory table and simultaneously caused to revolve about their axes, while subjected to the deposition of material sputtered from above. The endwise movement can be stopped by closing gates at the end of the grooves, in order to prolong exposure to sputtering. The blanks are loaded in a central hopper of a round table vibrated by a torsional vibrator of the type used for tangential feeders. The grooves are offset from the radial direction so that the vibration of the table will impart slight outward impulses to the blanks, which are additionally led forward by a slight downward slant of the grooves. The grooves are semicylindrical and a few per cent larger in diameter than the blanks in order to produce a smooth rolling motion.

United States Patent, 1 1

Greenlay et al.

p111 3,755,133 v [451 Au 28,1973

Northern Electric Company, Limited, Montreal, Quebec, Canada Filed: June3, 1971 Appl. No.: 149,442

[73] Assignee:

198/33 AA, 198/220 BC Int. Cl. C23c 15/00 Field of Search 204/192, 298;

198/33 AA, 30 AA, 220 BC; 118/49, 320

References Cited UNITED STATES PATENTS 7/1965 Manderbach 198/33 AA9/1967 Skowron 198/33 AA 3,421,924 1/1969 Harlam et al. 198/33 AA [57]ABSTRACT I Cylindrical ceramic blanks are fed endwise down grooves in avibratory table and simultaneously caused to revolve about their axes,while subjected to the deposition of material sputtered from above. Theendwise movement can be stopped by closing gates at the end of thegrooves, in order to prolong exposure to sputtering; The blanks areloaded in a central hopper of a round table vibrated by a torsionalvibrator of the type used for tangential feeders. The grooves are offsetfrom the radial direction so that the vibration of the table will impartslight outward impulses to the blanks, which are additionally ledforward by a slight downward slant of the grooves. The grooves aresemicylindrical and a few per cent larger in diameter than the blanks inorder to produce a smooth rolling motion.

15 Claims, 8 Drawing Figures um I UH l i Q i v will!!!MIIII-IIIIII'IIIIIIIIA MW w J ill PATENTEDMIBZB Ian f I sum 3 or 4'DEVICE FOR EXPOSING SMALL'ROLLABLE nomss'ro spurrsnmc This inventionrelates to the formation of films on the cylindrical surfaces ofelongated small cylindrical bod ies, and more particularly to theformation of film type electrical components on cylindrical insulatingblanks by sputtering techniques.

In recent years, film type electrical resistors using metallic orpartially oxidized metallic film, in which the metal may be zinc ortantalum for example, deposited on an insulatingjsubstrate such as highquality ceramic, have acquired a certain preference in the electronicsindustry because of therelatively high stability of their electricalcharacteristics. A preferred method forthe manufacture of such film typeelectronic components has been sputtering in high vacuum under theinfluence of a strong electric field, with an electrode of the materialto sputtered serving as a cathode, and with the work or the work supportas the anode. The sputtering process lends itself readily to themanufacture of films of the desiredthickness on flat ceramic or glasssubstrates and in the case of resistors, the higher values of resi'sancecan be made by etching, leavinga zig-zag film path for the activeportion. There is, however, a continuing interest in manufacturing filmtype components on cylindrical ceramic substrates because of thecompact'nature of such components and the 'easeof obtaining a wide rangeof values with such components by a helixing operation that lends itselfeasily to accurate automatic control.

In order to manufacture cylindrical film type components by sputteringtechniques, the necessity of evenly exposing cylindrical surfaces torectilinear or radial sputtering has posed difficult problems. Onesolution has been to take advantage of the hollow core frequentlyprovided on cylindrical ceramic blanks in order to support amultiplicity 'ot'b'lanks axially end to end on an array of turning rods,but the loading and unloading "of such a sputtering apparatus isnecessarily time consuming.

This invention provides a supporting electrode for cylindrical blanksundergoing sputtering which will both advance the blanks from an inputhopper to an output hopper and also rotate them about their axis whileadvancing through the sputtering zone. In addition, agate may beprovided to arrest the progress of the blanks't'hrough the sputteringzone, while they continue to be caused to rotate to exposetheircy'lindrical surfaces uniformly to sputtering. This is accomplishedby feeding the blanks into round-bottom grooves slightly wider'than theblanks and inclined to lead the blanks by gravity towards the outputhopper and providing a vibration transverse to the grooves preferablyslightly off the perpendicular to the grooves, with an asymetricalvibratory momentum to cause the cylindri cal blanks 'to rotate abouttheir axes. The machine works better if the vibration imparts a slightforward motion to the blanks, although most of the force imparted isused to produce rotation. We prefer "to accomplish this operation on around supporting table with grooves, fanning outward from the center,that are not strictly radial, but rather such thatthey were extendedinward they would 'be tangent to a circle about the center. Thisstructure lends itself readily to the provision of a central loadinghopper and a receiving hopper at a chosen :point on the periphery andalso to inthe. apparatus shown in FIG. 1;

stallationsof the equipment in a cylindrical bell jar type.vacuumenclosure, with the sputtering cathode at the blanks;

FIG.- 2 is a perspective view of the vibrating table of FIG. 3 istransverse cross-section of one of the grooves of the table with acylindrical blank, also shown in section, seated in the groove;

FIG. 4 is a plan view of the table with part of the centralsuperstructure removed and another part shown in section;

FIG. v5, appearing with FIGS. 2 and 3, is a partial perspective view ofthe inner portion of the table with a covering element removed;

FIG. 6 is a part of a radial vertical section of the table;

FIG. 7 is part of a vertical section of the table taken along the axisof one of the grooves, and

FIG. 8, appearing with FIGS. 2 and 3, is a transverse section of aportion of the table along the line 8-8 of FIG. 7.

As shown in FIG. 1, the sputtering process is conducted in an evacuatedenclosure I typically enclosed by a domed glass cylinder 3 mounted on abase 4 with a demountable vacuum seal 5. Means for establishing,maintaining and releasing the vacuum are not shown but it is understoodthat these will normally be provided going through the base 4 and thatthe sub-base 6 will have appropriate perforations and/or channels forthese facilities. The electrical connections are likewise not shown andthey would similarly be brought out through the base 4, not only tosupply the high voltage for generating the sputtering phenomenon, butalso for engergizing the actuator 10 of a vibrating table 12 and foractuating the gate solenoids 14 the function of which will be describedlater.

A mesh screen, not shown, may be provided over all or much of thesurface of the glass enclosure 3 to limit the high voltage field to theinside of the enclosure. Such a screen would naturally be grounded.

An insulated structure 18, preferably made entirel 'out of insulatingmaterial so as not to disturb the electric field, suspends the annularcathode 20, which is shown in cross-section so that its shape may beapparent. At least the lower surface of this electrode is made of themetal to be sputtered. It is held far enough above the table 12 so thatany distortion of the electric field by the central loading hopper 22will not disturb the downward sputtering direction of the particles ofmetal shown by the arrows in the drawing.

The table 12 is mounted on four oblique stiff leaf springs 24 connectinga heavy base block 26 with a square mounting block 28 inthe well knownarrangement of torsional vibrators. Beneath the block 28 is suspendedthe armature 30. A narrow air gap 32 separates armature 30 from actuator10. Alternating current through coil 34 of actuator 10 will impose avertical vibratory force on armature 30 and springs 24 will cause thevibration of the table 12 to be torsional in nature, with a relaxationtype of characteristic tending to impart a unidirectional tangentialmomentum to particles on the surface of the table.

FIG. 2 shows the surface of the table 12 in perspective. The grooves 36are not radial. They radiate from the central area surrounding thehopper 22, but they are tangent to a small circle concentric with thecircumference of the table. The diameter of the table is preferablybetween 1 and 2 feet and the diameter of the circle to which the groovesare tangent is about 1 inch. The circle to which the grooves are tangentis most appropriately related to the outer diameter of the distributionarea which feeds the grooves. Such a relation fixes the angle of thegrooves to the radii that they intersect at their innermost ends. Inthese terms, our findings are that the diameter of the circle to whichthe grooves, or their center lines rather, are tangent, is

. preferably between an eighth and a quarter of the diameter of thelargest circle that can be inscribed in the distribution area (e.g. thecircle which defines the inner ends of the grooves). The central inputhopper is part of a distributing head for the blanks to be treated. Itis a cylindrical container mounted on the table 12 with a series ofbroad slots just above the level where the container meets the surfaceof the table, to permit the cylindrical blanks loaded into the containerto spread out on the surrounding surface of the table and to feed intothe grooves 36. It has a cover 50 removable for loading. The outerdistributing zone has a fixed cover 40 to shield the blanks fromsputtering at this stage.

FIG. 3 is a transverse cross-section of a groove with a cylindricalblank in it, illustrating the action of the table. The operative roundbottom groove 36 is preferably semi-cylindrical. The bottom of thegroove is not horizontal, but rather inclined slightly to lead blankstowards the edge of the table. Even where the groove is nearest the topsurface of the table 12 it should be deep enough to be semi-cylindrical.It is therefore convenient to provide additional grooving in the form ofshallower curved surfaces 38 above at least the deeper parts of thegroove so that the working groove will be semi-cylindrical along itswhole length. Instead of providing the broader curved surfaces 38, theupper surface of the table 12 could be very slightly conical, lower atthe edge than in the center, so that the grooves 36 could besemi-cylindrical, flush with the surface and also slanted the rightamount downwards. The downwards inclination is preferably of the orderof 3".

The diameter of the grooves 36 is only slightly larger than that of theblanks to be treated in the apparatus, one of which is shown incross-section at 39 in FIG. 3. The movement of the table 12 is such asto propel particles on its surface to the left, viewed from the edge(solid arrow at right on FIG. 3). The rotation imparted to thecylindrical blanks is clockwise, viewed from the edge of the table(curved arrow, FIG. 3). If the grooves are too wide, the blanks will becaused to roll around somewhat irregularly. We prefer a gorove diameterabout percent greater than the diameter of the blanks to be treated.

FIG. 4 is a top view of the table with the cover 40 removed. Dashedcircles 41 and 42 enclose the area where the flange 43 of cover 40 fitsover the table.

Dashed circles 45 and 46 are the projection of the walls above the levelof the table, so that only the posts 47 between the slots 48 are present at this level.

FIG. 5 shows a few blanks 51 in the portion of the table where theblanks are distributed into the various grooves 36. The arrow 53 showsthe direction in which the blanks 51 impelled by the motion of table 12as they come out by gravity through the elongated apertures 48 of thehopper 22. The momentum imparted to the blanks is tangential and,besides, there is a slight outward slope to the surface on which theymove after coming out of hopper 22, so that by a combination of forcesthe'blanks 51 are propelled into the grooves 36. The vibratory motion ofthe table keeps the blanks from sticking in place by friction and makesthem sensitive to the effect of the small inclination of the surfaces onwhich they move.

When the machine is in use, the blanks come out of the hopper 22 closetogether and rather completely fill the distribution area just outsidethe hopper. The ends of the lands 55 are faired away to open up eachgroove on the side from which the blanks come to it. This shaping servesto lead the blanks easily into the grooves. When the distribution areais well filled with a single layer of blanks, all the grooves arecontinuously fed with blanks. Even as the supply of blanks runs out, thecombined rotation, vibration and advancement irnparted in the grooves bythe motion of the table, together the inclination of the surfaces, keepsthe blanks progressing and rotating smoothly in the grooves.

FIG. 6 is a radial cross-section of the distribution area of the table12. Hopper 22 is shown fitting into a central hole in the upper memberof the table into which the grooves 36 are cut. One of these issectioned at a small angle to its axis, so that the surface of its farside and one of the surfaces 38 appear in FIG. 6.

An insert 61 provides a floor for the hopper 22 and preferably has aconical surface 62 somewhat steeper than the downward inclination of thegrooves and distribution area of the table 12. A central machine screw65 (and lock washer, not shown) holds the insert 61 in place and alsoserves to hold the spacing disc 66 to the square block 28 which isactuated by the armature 30 in cooperation with the springs 24 (FIGS. 1and 2). Ma chine screws 70 located on the lands between the grooves 36serve to hold the upper portion 60 of the table 12 to the spacing disc66 and the square block 28.

As shown in FIG. 7, the purpose of the spacing disc 66 is to provide aperipheral channel 71 on the upper surface of the lower member 72 of thetable 12 between the circumference of disc 66 and a retaining lip 74provided on the circumference of the disc 72. The ends of the groove inthe upper member 60 of the table have gate apertures 75 of such size asto permit a treated blank to drop through to the channel 71 and a gateshutter 77 is provided for the purpose of controllably opening orclosing the gates 75. The shutter 77 is a flat annular member withapertures that may be brought into register with the gate apertures 75and it is mounted on a plurality of supports, such as support 78 shownin FIG. 7. These supports project through slots 79, which are shaped topermit sufficient rotary movement of the shutter 77 to enable it to openor close the gates 75.

The shutter 77 is actuated by the solenoids 14, one of which is adaptedto pull the shutter around to open the gates 75 and the other of whichis adapted to pull it back in the opposite direction to close them. Inorder that the solenoids l4may-be mounted on the underside of the lowermember 72of the table 12, the armatures 80 of the solenoid 14 areprovided with actuatordetails 82 for transmitting the motion of thearmatures to the shutter 77.

FIG. 8-shows a cross-section along the lines 8-8 of FIG. 7.

When the treated blanks are permitted to drop through the gates 75 intothechannel 7'l,the vibratory motion of the table then propels them inthe channel 71 around the table until theyare gathered by the outputhopper 23, into which they fall.

The shutter 77 serves to permit the sputtering of the blanks to beprolonged in the event that a straightforward passage through the groove36' would not build up a sufficiently heavy film'of the sputteredmaterialon the. blanks. In that case, the shutter can beclosed exceptfor intervals just longenough to-drop into the channel 7lithose blankswhich have been sputtered since the last opening of the shutter, and theblanks can be held on the table 12 for the necessary length of time tobuild up the desired film. When the shutter is closed, theblanks-willsimply rotate in the grooves 36. As soon as the sutter opens and the endblank falls through the gate 75, the forward progress of the blanks inthe grooves is resumed. It is difficult to design the gate so as to keepthe end blank rotating when the gate is shut and we prefer to place thegate beyond sputtering range or to'provide the gates with a cover (notshown).

We recognize that of course an apparatus of a similar design couldbemade inwhich the blanks move from the outside of the table to theinside, in which case the angle of the grooves to the radius of thetable should be in the opposite sense, assuming that the direction inwhich particles on the table are propelled remains the same. Blankscould also be caused to advance in'long parallel grooves and subjectedto a transverse vibration, in which case again the direction ofvibration should be somewhat off the perpendicular to the axes of thegrooves, in the direction such as to give the blanks a slight forwardcomponent from the vibration to add to the gravity effect from theslight inclination of the grooves. The form of apparatus here shown,however, is preferred because it not only provides a smooth rotation andadvancement of the particles over a considerable range of vibrationamplitude, but it provides a simple loading system adapted to keep allthe grooves filled as the process goes on and a collecting system whichmakes use of the same motion of the table that isused to cause therotation of the blanks.

The speed of the rotation of the blanks can be controlled by a variableautotransformer controllingthe alternating current supplied to theactuator 10. By thus varying the powerinput, the blanks in the groovescan be made to rotate slowly, at moderate speed, or fast. We prefer tohave them rotate at moderate speed during processing so that in theunlikely case that some of the apertures 48 get jammed during operation,the

. power input to the actuator 10 can be momentarily raised to an inputcorresponding to a high rotation speed of the blanks, so that theadditional agitation in the hopper 22 will clear the apertures.

Aluminum is preferred as a material for the upper member 60 of the table12 because sputtered metals used in'the process do not stick to it, sothat the table is easily cleaned after use. Similarly, aluminum ispreferred for the hopper 22 and itscover 50 and for the cover'40'for-.thedistributing areaof the table l2.

Pulse-rotatory holding-device's of this invention such as the oneillustrated in the drawings are not limited to manipulating cylindricalblanks. Various types of rectilinearly rollable bodies such as prolatespheroids of material, spherical bodies, or helical bodies of at leasttwo turns, or dumbbell shaped bodies can be handled, so long as therolling diameter is a few percent smaller than that of the grooves.These various types of bodies can thus be exposed to application ofmaterial or influences from above and, if desired, simultaneouslyadvanced across the exposure zone by the-same type of grooved vibratingtable.

The grooves 36 are preferably cylindrical in shape in the strictestsense, that is, semicircular in cross-section, although a semi-elipticalcross-section would be operable if the major axis is horizontal and theeccentricity is small. The bodies to be handled by the table must beable to roll freely and in a straight line on a flat surface and theirlength must be at least equal to the rolling surface diameter andpreferably considerably] in excess thereof, so that they will not topplein the axial direction as the result of forces propelling them axially.

A' frustoconical body would not meet these requirements. A symmetricalbase-joined biconical body could be handled by the device after afashion but its instability of rolling might make its motion irregular.On the other hand a prolate spheroid or a ball would givenodifficulties. We maydescribe the bodies to be handled by machines ofourinvention as rollable to express the meaning just explained and thequalification rollable in a straight line is to be understood. It isalso to be understood that a rollable body as meant herein has dimensionalong the axis of rolling at least as great as the rolling diameter, andusually considerably greater{ While grooves 36 of thepreferredembodiment disclosed herein are straight, they could be curved-to achieve greater length in the same table diameter and greater dwellof the bodies movingtherealong in the sputtering region.

What is claimed is:

l. A machine for exposing to treatment the peripheral surface ofrollable bodies comprising;

a. a grooved vibratory table, having round bottom grooves slightlyinclined to the horizontal and of a diameter slightly in excess of therolling diameter of said bodies b. a distributing head adapted to beloaded with said bodies and to distribute them to the upper ends of saidgrooves of said table;

c. means for vibrating said table with a dynamically asymetric vibrationgenerally transversely of said grooves and having a small componentthereof in the direction of descent of said grooves whereby said bodiesare caused to rotate in their rolling mode and influenced also todescend said grooves,

d. means for treating the peripheral surfaces of said bodies as exposedin said grooves, and e. means for collecting'said bodies after theyarrive at the lower ends of said grooves. 2. A machine as definedin'claim l in which the said round bottom grooves are straight.

3. A machine as defined in claim 2 in which each of said groovesterminates at its lower end in a gate and in which there is a shutteradapted to open and to close said gates simultaneously for alternativelyarresting the progress of said bodies down said grooves or permittingthem to proceed to said collecting means.

4. A machine for exposing to treatment the peripheral surface ofrollable bodies comprising:

a. a torsional vibrator of the type adapted to propel particlestangentially on a surface carried thereby,

b. an output feeder carried by said vibrator having a peripheral channeland an output orifice therefrom,

c. a grooved treatment table superposed on said output feeder having adistribution depression for said bodies at its center, a multiplicity ofround-bottom grooves slightly wider than said bodies extending outwardlyand slightly downwardly from said depression and leading outwardly awaytherefrom in a direction diverging, at a small angle, from the radialdirection towards the direction of propulsion of said vibrator,

d. an aperture located over said channel of said feeder at the outer endof each of said grooves, of

a size adapted for passage of said bodies one at a time from the grooveto said channel of said feeder,

e. a distributing head including a loading hopper mounted over saiddepression, and

f. a collecting container disposed below said output orifice of saidfeeder.

5. A machine as defined in claim 4 in which said grooves are straightand semicylindrical.

6. A machine as defined in claim 5 in which the edges of said groovesare at least in large part below the upper surface of said table and arebordered by lateral bench surfaces lowering the table surface in theimmediate neighborhood of said groove edges.

7. A machine as defined in claim 6 in which said bench surfaces areconcave and cylindrical.

8. A machine as defined in claim 4 which the lands between the saidgrooves are faired away where the grooves meet said distributiondepression, said fairing being solely or perponderantly on that side ofa groove from which said bodies tend to arrive to it as the result ofbeing impelled tangentially in the outer part of said distributiondepression by said vibrator.

9. A machine as defined in claim 4 in which said loading hopper iscylindrical at least in its lower portion and has a floor higher in thecenter than at its periphery, which at said periphery is flush with andcommunicates with said distribution depression through openings adaptedfor feeding said bodies in a single layer to said distributiondepression.

10. A machineas defined in claim 9 in which the floor ofsaiddistribution depression is inclined slightly, in a very flat conicalmanner so that-the outer part is a little deeper than the inner.

11. A machine as defined in claim 4 which also includes a shuttermounted at the underside of the outer portion of said table operable tohold either of two positions, one of which blocks all of said aperturesand the other of which leaves all of saidapertures open, and means foroperating said shutter.

12. A machine as defined in claim 11 in which said means for operatingsaid shutter are remotely controllable.

13. A machine as defined in claim 11 in which said means for operatingsaid shutter are a pair of solenoids, each of which is adapted to pullsaid shutter into one of its positions.

14. An apparatus for treating the peripheral surface of rollable bodiescomprising:

a. a base;

b. a machine as defined in claim 4 mounted on said base;

c. an enclosure removably supported on said base and forming therewith agas tight enclosure surrounding said machine; and

(1. means for establishing an environment within said enclosure to whichsaid bodies are exposed for treatment.

15. An apparatus as defined in claim 14 for electrostatic sputtering ofcylindrical cores in high vacuum further comprising:

e. a pressure seal on said base adapted to permit said enclosure to beopened when vacuum is released;

f. means for opening and closing said enclosure when no vacuum ispresent; and

g. means for initiating, controlling and arresting the operation of saidmachine from outside said enclosure,

said means for establishing an environment within said enclosurecomprising:

h. a high voltage sputtering electrode mounted on said base at adistance above said base;

i. means for establishing a high vacuum in said enclosure, formaintaining the same and for releasing the same; and

j. means for appyling sputtering voltage to said electrode.

e e s r s:

1. A machine for exposing to treatment the peripheral surface ofrollable bodies comprising: a. a grooved vibratory table, having roundbottom grooves slightly inclined to the horizontal and of a diameterslightly in excess of the rolling diameter of said bodies b. adistributing head adapted to be loaded with said bodies and todistribute them to the upper ends of said grooves of said table; c.means for vibrating said table with a dynamically asymetric vibrationgenerally transversely of said grooves and having a small componentthereof in the direction of descent of said grooves whereby said bodiesare caused to rotate in their rolling mode and influenced also todescend said grooves, d. means for treating the peripheral surfaces ofsaid bodies as exposed in said grooves, and e. means for collecting saidbodies after they arrive at the lower ends of said grooves.
 2. A machineas defined in claim 1 in which the said round bottom grooves arestraight.
 3. A machine as defined in claim 2 in which each of saidgrooves terminates at its lower end in a gate and in which there is ashutter adapted to open and to close said gates simultaneously foralternatively arresting the progress of said bodies down said grooves orpermitting them to proceed to said collecting means.
 4. A machine forexposing to treatment the peripheral surface of rollable bodiescomprising: a. a torsional vibrator of the type adapted to propelparticles tangentially on a surface carried thereby, b. an output feedercarried by said vibrator having a peripheral channel and an outputorifice therefrom, c. a grooved treatment table superposed on saidoutput feeder having a distribution depression for said bodies at itscenter, a multiplicity of round-bottom grooves slightly wider than saidbodies extending outwardly and slightly downwardly from said depressionand leading outwardly away therefrom in a direction diverging, at asmall angle, from the radial direction towards the direction ofpropulsion of said vibrator, d. an aperture located over said channel ofsaid feeder at the outer end of each of said grooves, of a size adaptedfor passage of said bodies one at a time from the groove to said channelof said feeder, e. a distributing head including a loading hoppermounted over said depression, and f. a collecting container disposedbelow said output orifice of said feeder.
 5. A machine as defined inclaim 4 in which said grooves are straight and semicylindrical.
 6. Amachine as defined in claim 5 in which the edges of said grooves are atleast in large part below the upper surface of said table and arebordered by lateral bench surfaces lowering the table surface in theimmediate neighborhood of said groove edges.
 7. A machine as defined inclaim 6 in which said bench surfaces are concave and cylindrical.
 8. Amachine as defined in claim 4 which the lands between the said groovesare faired awAy where the grooves meet said distribution depression,said fairing being solely or perponderantly on that side of a groovefrom which said bodies tend to arrive to it as the result of beingimpelled tangentially in the outer part of said distribution depressionby said vibrator.
 9. A machine as defined in claim 4 in which saidloading hopper is cylindrical at least in its lower portion and has afloor higher in the center than at its periphery, which at saidperiphery is flush with and communicates with said distributiondepression through openings adapted for feeding said bodies in a singlelayer to said distribution depression.
 10. A machine as defined in claim9 in which the floor of said distribution depression is inclinedslightly, in a very flat conical manner so that the outer part is alittle deeper than the inner.
 11. A machine as defined in claim 4 whichalso includes a shutter mounted at the underside of the outer portion ofsaid table operable to hold either of two positions, one of which blocksall of said apertures and the other of which leaves all of saidapertures open, and means for operating said shutter.
 12. A machine asdefined in claim 11 in which said means for operating said shutter areremotely controllable.
 13. A machine as defined in claim 11 in whichsaid means for operating said shutter are a pair of solenoids, each ofwhich is adapted to pull said shutter into one of its positions.
 14. Anapparatus for treating the peripheral surface of rollable bodiescomprising: a. a base; b. a machine as defined in claim 4 mounted onsaid base; c. an enclosure removably supported on said base and formingtherewith a gas tight enclosure surrounding said machine; and d. meansfor establishing an environment within said enclosure to which saidbodies are exposed for treatment.
 15. An apparatus as defined in claim14 for electrostatic sputtering of cylindrical cores in high vacuumfurther comprising: e. a pressure seal on said base adapted to permitsaid enclosure to be opened when vacuum is released; f. means foropening and closing said enclosure when no vacuum is present; and g.means for initiating, controlling and arresting the operation of saidmachine from outside said enclosure, said means for establishing anenvironment within said enclosure comprising: h. a high voltagesputtering electrode mounted on said base at a distance above said base;i. means for establishing a high vacuum in said enclosure, formaintaining the same and for releasing the same; and j. means forappyling sputtering voltage to said electrode.